Feeding device for percussive motors



[ 3 w. A. SMITH, SR 1,786,135

FEEDING DEVICE FOR PERCUSSIVE MOTORS Filed March 11, 1930 \l b I l 22 W W;

\\H;J\\\\ L 7 1 1 1.11. 0

H15 ATTORNEY.

I l INVENTOR.

s HM 1422' 'amAdm/Zzki 6'1:

Patented Dec. 23, 1930 UNITED STATES Application filed March 11, 1930. Serial No. 434,958.

This invention relates to feeding devices, but more particularly to a device of this character adapted for actuating a percussive motor relatively to its support.

One object of the invention is to utilize the force of the reciprocatory hammer piston of the motor for actuating the motor along its support.

Another object is to prevent recoil of the motor upon reversal of the hammer piston at v the end of one stroke and to enable the motor to be moved along the support by the piston upon the reversal of the piston at the end of its return stroke.

Another object is to enable the motor to be thus actuated selectively for either advancing or retracting the motor with respect to its support.

Still another object is to obtain a rugged and efficient feeding device which will be fully capable of withstanding the severe usage to which devices of this character are subjected and which comprises only a'few parts of simple design, so that, in consequence, the device will be inexpensive to manufacture and to maintain.

Other objects will be in part obvious and in art pointed out hereinafter.

n the accompanying drawings illustrating the invention and in which similar reference characters refer to similar parts,

Figure 1 is a side elevation of the invention showing it applied to a motor and its support,

the motor and support being shown partlybroken away, I

Figure 2'is a plan view partly in section, and I Figure 3 is a transverse view taken through Figure 1 on the line 33 looking in the direction indicated by the arrows. j

Referring more particularly to the drawings, A esignates a motor which,:for thepurpose of this invention, is illustrated as a rock drill mounted slidably on a support B illustrated as a rock drill shell. The motor A comprises the usual cylinder 0 wherein is disposed a reciprocatory hammer piston D to deliver blowsof impact against a working implement (not shown).

The support or shell B may be provlded der C which extends through with the usual guideways E to receive slidable ribs F arranged on opposite sides of the rock drill, as for instance, on the cylinder C for guiding the rock drill in the shell.

The cylinder C may be provded with the usual back head G which may be clamped to the cylinder by means of side rods or bolts H 'sposed on opposite sides of the cylinder in a well known manner. Among other functions the back head Gr may serve as a housing for a throttle valve J, only the stem of which is indicated.

The throttle valve J may be of a suitable .type commonly employedfor controlling the admission of pressure fluid froma source of supply into the rock drill. The distribution of such pressure fluid to the ends of the cylinfor actuating the piston D may be controlled by any suitable distributing valve mechanism (not shown).

In accordance with the present invention, means are provided for enabling the motor A to be actuated longitudinally of the support by the jar resultlng upon the reversal of the hammer piston D at the end of the strokes of-said piston. To this end a rack K is disposed inthe support B to which it may be secured in any suitable manner, as for instance, by screws L. The rack K may, if desired, extend throughout the entire length of the support B and, in the present instance, the rear end of the rack K extends rearwardly of the corresponding end of the shell B and is supported by a cross head 0 which in turn is supported by the usual standards P.

Preferably the rear end Q of the rack K or, in other words, that portion of the rack the cross head 0 is threaded to receive a nut R whereby the rack K and the cross head may be clamped securely together. At the juncture of the portion Q of the rack K may be formed a flange or collar S to seat against the inner surface of the cross head 0.

Secured to the rear end of the back head G, as by means of the supply bolts H, is a bearing T which has a pair of rearwardly extending parallel arms U and V to form bearings for a shaft Wto which is keyed a gear X. The gear X meshes with the rack K and may be provided with suitable hub members Y on opposite sides thereof to abut the inner surfaces of the arms U and V for preventing lateral movement of the gear.

Means are provided for preventing rotation of the gear X and therefore recoil of the motor A during the time the piston D reverses the direction of its stroke in the ends of the cylinder C. The means provided for this purpose are adapted to act to either prevent recoil of the motor due to the imparted thereto by the piston D at the end of its rearward stroke whenever it is intended to feed the motor forwardly in the direction of the work, or to prevent recoil of the motor A in a forwardly direction upon reversal of the piston D in the front end of the cylinder C whenever it is intended to utilize the jar imparted to the motor by the piston D for retracting the motor relatively to the support B. In furtherance of this end a ratchet wheel Z is keyed to an end 6 of the shaft V which projects from the side of the arm V of the bearing T. The ratchet wheel Z may be held against endwise movement in any suitable manner, as for instance, by means of a nut c which is threaded on the end I) of the shaft.

On the side of the arm V is a toggle designated generally by (Z and comprising a ratchet c which is pivoted to the arm V by means of a screw f. The ratchet e in this instance is provided with'a pair of diverging arms g and h, the end surfaces and 70 respectively of which are adapted to engage teeth 0 of the ratchet wheel Z. The ratchet e is provided with a stem 2) on which is slidably arranged a sleeve 9 carrying a lever 0" whereby the ratchet 0 may be shifted from one limiting position to the other.

The sleeve 9 is further provided with a pivot pin 3 which extends into an aperture t of a link a pivoted with its opposite end on a screw o threaded into the side of the bearing T. The arrai'igement of the toggle device is such that when the ratchet is shifted from one position to the other the stem 7) will slide through the sleeve 9'. In order to hold the ratchet c and the link it in the elf-center position a spring to is disposed upon the stem 7) to bear with one end against the sleeve g and with its other end against a shoulder a: on the ratchet e.

The operation of the device is as follows:

Let it be assumed that the motor A is in operation so that the hammer piston D is reciprocating rapidly within the cylinder C to deliver its blows to a working implement, as for instance, a drill steel. hen the motor A is being thus utilized, it is, of course, essential that it be actuated longitudinally of the support B in the direction of the working implement so that the full force of the blow of the hammer piston may be effective ly applied thereto to drive it into the work.

In order to constantly insure this position of the motor with respect to the working implement the toggle (Z may be rocked to the position illustrated in Figure 1, in which the end surface 7: of the arm it will extend into the path of the teeth 0 of the ratchet wheel. In this position of the ratchet c the ratchet wheel Z and therefore the gear X will be permitted to rotate only in a counterclockwise direction, as Figure 1 is viewed so that when the piston D reverses its direction of movement in the front end of the cylinder C the jar resulting from the act of reversal will, by acting against the motor A, carry the said motor bodily in the direction of the work.

The gear X being carried by the motor will then advance along the rack K in accordance with the degree of penetration of the working implement into the work. Likewise, the ratchet wheel Z will be rotated and displace the ratchet the teeth thereof will arm h. Such movement of the ratchet arm 71,. however, will be constantly resisted by the spring to which will act to quickly restore the ratchet e to a position in which the end surface 70 of the ratchet arm it will lie or extend into the path of the teeth 0. The arm it will thus form an abutment for the teeth 0 to prevent rotation of the ratchet wheel Z and the gear X and therefore also to prevent retrograde movement of the motor A upon the application of the jar imparted to the motor by the piston D during the reversal of the piston at the end of its rearward stroke. With the arm h of the ratchet 6 extending into the path of the teeth 0 the motor A can only be carried in a forwardly direction along the support B by the piston D.

After the motor A has advanced in a forwardly direction for the required distance and it is desired to retract the motor relatively to its support the position of the toggle cl may be changed, as by means of the lever r, so that the arm it will be retracted and the arm 9 will be rocked into the path of the teeth 0. In the new position of the ratchet e the end surface of the arm f/ will engage the teeth 0 and prevent the gear X from rotating in a forwardly direction upon reversal of the piston D in the front end of the cylinder C. The gear X and the ratchet wheel Z will, however, be capable of rotating in a clockwise direction so that when the piston D reverses in the rear end of the cvlinder C the jar resulting from such reversal and acting against the motor A will cause the said motor to be rapidly actuated rearwardly. After the motor A has travelled rearwardly for the required distance the admission of pressure fluid to the motor may be cut off by means of the throttle valve J, thus bringing the piston D and, consequent ly, the motor A to rest.

lltl

I claim:

1. In a feeding device, the combination With a motor and a support whereon said motor is slidably mounted, a re'ciprocatory hammer piston in the motor imparting jars thereto tending to move the motor longitu dinally of the support, of recoil resistance means operatively associated with the motor and the support and comprising a rack and a gear meshing with the rack, and stop means for controlling the direction of rotation of the gear to enable the motor to be advanced and retracted with respect to the support by the piston.

2. In a feeding device, the combination with a motor and a support whereon said motor is slidably mounted, a reciprocatory hammer piston in the motor imparting jars thereto tending to move the motor longitudinally of the support, of a rack mounted on the support, a gear carried by the motor and meshing with the rack, and stop means for controlling the direction of rotation of the gear to enable the motor to be advanced and retracted with respect to the support by the piston.

3. In a feeding device, the combination with amotor and a support whereon said motor is slidably mounted, a reciprocatory hammer piston in the motor imparting jars to the motor upon-reversal of the piston at the ends of its strokes tending to actuate the motor longitudinally of the support, of a rack, a gear carried by the motor and meshing with the rack, and stop means for controlling the direction of rotation of the gear and thus also the direction of movement of the motor With respect to the support.

4. In a feeding device, the combination With a motor and a support whereon said motor is slidably mounted, a reciprocatory hammer piston in the motor imparting jars thereto tending to move the motor longitudinally of the support, of a rack mounted on the support, a gear carried by the motor and mesh: ing with the rack, a ratchet wheel connected to rotate with the gear, and means acting against the teeth of the ratchet wheel for holding the gear stationary and thus prevent recoil of the motor upon reversal of the piston at the end of a stroke in one direction.

5. In a feeding device, the combination With a motor and a support whereon said motor is slidably mounted, a reciprocatory hammer piston in the motor imparting jars thereto tending to move the motor longitudinally of the support, of a rack mounted on the support, a gear meshing with the rack, a bearing for the gear and being carried by the motor, a ratchet wheel connected to rotate with the gear, a ratchet mounted on the bearing to form an abutment for the teeth of the ratchet Wheel, and means for reversing the ratchet for selectively controlling the direction of rotation of the gear and thus also the direction of movement of the motor with respect to the support.

6. In a feeding device, the combination with a motor and a support whereon said motor is slidably mounted, a reciprocatory hammer piston in the motor imparting jars to the motor upon reversal of the piston at the ends of its strokes tending to actuate the motor longitudinally of the support, of a rack mounted on the support, a bearing carried by the motor, a gear supported by the bearing and meshing with the rack, a ratchet Wheel connected to be rotated by the gear, a ratchet pivoted on the bearing to form an abutment for the teeth on the ratchet Wheel and being adjustable to different positions for selectively controlling the direction of rotation of the gear and thus also the direction of movement of the motor with respect to the support, and means for maintaining the ratchet in placed position.

7. In a feeding device, the combination with a motor and a support whereon said motor is slidably mounted, a reciprocatory hammer piston in the motor imparting jars to the motor upon reversal of the piston at the ends of its strokes tending to actuate the motor longitudinally of the support, of a rack mounted on the support, a bearing carried by the motor, a gear supported by the bearing and meshing with the rack, a ratchet wheel connected to be rotated by the gear, a ratchet pivoted on the bearing to form an abutment for the teeth on the ratchet wheel and being adjustable to different positions for selectively controlling the direction of rotation of the gear and thus also the direction of movement of the motor with respect to the support, toggle means for holding the ratchet in placed position and comprising a stem on the ratchet and a link pivoted at one end to the stem and at the other end to the bearing, and a spring on the stem acting against the link to hold said link and the ratchet in off-center positions.

In testimony whereof I have signed this specification.

WILLIAM A. SMITH, SR. 

